1. Field of the Invention
The subject invention relates to fluid filtration devices, and more particularly, to an encapsulated fluid filter cartridge assembly including an outer shell having an expansion joint integrally formed therein which is adapted and configured to facilitate the expansion of the shell within a cartridge housing.
2. Background of the Related Art
Filtration systems having filter heads which employ permanent filter housings and replaceable filter cartridges are well known in the art and have been employed for many years to filter contaminated fluids. An early example of this type of system is disclosed in U.S. Pat. No. 2,858,026 to Lorimer. In such a system, the filter housing serves both as a pressure vessel to support the filter cartridge and a sump or bowl to receive contaminated fluid to be filtered. Consequently, when the filter cartridge is removed from the filter housing after a period of prolonged use, the housing remains contaminated.
Those skilled in the art soon recognized the need to maintain the sterility of the filter housing and provided practical solutions to the problem, as disclosed, for example, in U.S. Pat. No. 3,648,100 to Close. The Close patent describes a system that includes a disposable filter cartridge consisting of a filter element encapsulated within a thin plastic shell and a metal housing that serves solely as a pressure vessel to support the filter cartridge. In use, contaminated fluid only flows though the filter cartridge, and the metal housing remains dry and sanitary.
Building upon the teachings of the prior art, and particularly, the teachings of the Close patent, the subject invention provides an encapsulated filter cartridge designed as a replacement cartridge for a filtration system of the type having a filter head that is unusually shaped and requires a fairly complex and uniquely designed cartridge to mate therewith. More particularly, the novel filter cartridge of the subject invention is configured to accommodate dimensional and geometric variations that often exist between mating components of a complex fluid filtration system. Furthermore, it is envisioned that the unique construction of the filter cartridge of the subject invention will facilitate and enable its employment as a relatively standardized replacement cartridge for a variety of filtration systems currently available in the marketplace.